User interfaces provide a mechanism by which a user may communicate with a computer system. One type of user interface is a graphical user interface. A graphical user interface relies on graphical objects, such as bars, buttons, icons, and visual text, to create a graphical representation of information with which a user may interact. For example, a user may instruct the software to save a document by moving an on-screen pointer over a save button and depressing a physical button (e.g., a physical button on a mouse). Alternatively, a user may use the ALT key, TAB key, ENTER key, and/or arrow keys to navigate a graphical file menu, presented to the user via the graphical user interface, and save the document.
A user may also navigate through a document using the graphical user interface. In particular, a user may use a graphical object, such as a scroll bar, to view different portions of the document. A scroll bar is a graphical object that includes a puck that slides across a bar typically located at the edge of a window. The size of the puck and the position of the puck on the trough visually identifies a percentage of the document displayed as well as an approximation of where the portion displayed exists within the document. By moving the puck, a user may navigate to a different portion of the document.